These studies represent collaborative projects with investigators interested in related issues which bear on sleep physiology. Included are a project showing decreased REM latency in panic-anxiety disorder patients, complementing a previous study here which showed the same process in obsessive-compulsive disorder patients. Following a long-term interest of the laboratory on sleep-related growth hormone secretion, patients with short stature and growth hormone neurosecretory dysfunction were found to have decreased number and amplitude of growth hormone pulses around the 24 hours, suggesting that there is a spectrum of GH regulatory dysfunction from absolute deficiency to irregularity of secretion. A variety of circadian rhythm studies continue, with evaluation of the sleep-waking aspects of longitudinal studies in patients with bipolar depressive illness and seasonal depression. In the latter group, seasonal variations in amounts of slow-wave sleep have been found.